A Rendezvous Node Selection and Routing Algorithm for Mobile Wireless Sensor Network

( Yifan Hu ),( Yi Zheng ),( Xiaoming Wu ),( Hailin Liu ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.10

Efficient rendezvous node selection and routing algorithm (RNSRA) for wireless sensor networks with mobile sink that visits rendezvous node to gather data from sensor nodes is proposed. In order to plan an optimal moving tour for mobile sink and avoid energy hole problem, we develop the RNSRA to find optimal rendezvous nodes (RN) for the mobile sink to visit. The RNSRA can select the set of RNs to act as store points for the mobile sink, and search for the optimal multi-hop path between source nodes and rendezvous node, so that the rendezvous node could gather information from sensor nodes periodically. Fitness function with several factors is calculated to find suitable RNs from sensor nodes, and the artificial bee colony optimization algorithm (ABC) is used to optimize the selection of optimal multi-hop path, in order to forward data to the nearest RN. Therefore the energy consumption of sensor nodes is minimized and balanced. Our method is validated by extensive simulations and illustrates the novel capability for maintaining the network robustness against sink moving problem, the results show that the RNSRA could reduce energy consumption by 6% and increase network lifetime by 5% as comparing with several existing algorithms.

원목을 활용한 아파트 실내디자인

후이판(제1저자) ( Yifan Hu ),이정교(교신저자) ( Jungkyo Lee ) 한국공간디자인학회 2015 한국공간디자인학회논문집 Vol.10 No.6

(연구배경 및 목적) 아파트는 현재 하나의 주거 형태로서 가장 보편적으로 자리 잡고 있다. 사회 발전과 사회 구조의 변화에 따라 현대인의 소득이 증가하고 문화 수준이 향상되면서, 현대인의 생활형태 및 주거 형태가 다양화되고 있다. 이에 따라 사람들의 아파트 소유가 증가하고 아파트 거래도 활발해졌다. 또한 생활수준의 향상과 더불어, 현대인들의 주거 공간에 사용되는 실내디자인의 재료가 다양화되면서 소비자들의 선택의 폭이 넓어졌다. 이러한 현상은 최근 실내디자인의 추세이기도 하다. 소비자의 요구가 변화하고 있는 현 시점에서 소비자의 요구에 맞는 아파트 실내디자인 연구가 이루어져야 할 것이다. 본 연구는 아파트 실내디자인의 대표적인 재료인 원목을 중심으로, 원목이 현대의 아파트 실내디자인에 활용된 기법을 찾고 분석할 것이다. 또한 향후 원목을 활용한 아파트 실내 디자인을 할 때, 본 연구를 참고재료로 활용하는데 그 목적이 있다. (연구범위 및 방법) 본 연구는 기존의 문헌조사와 선행조사를 통해 전통요소를 도입한 한국과 중국의 현대적인 아파트 실내디자인에서 원목을 활용하는 사례를 선택하였다. 이를 토대로 2013년부터 2015년까지 시민의 생활수준이 비교적 높고 물가가 비슷한 한국의 서울시와 중국의 북경시(北京市)를 대상으로 선정하였다. 더불어 서울시와 북경시에 소재하는 건설업체 중 소비자 인지도가 높은 아파트 모델하우스를 선정하였다. 한국과 중국의 8개의 아파트 실내디자인을 사례로서 선정하였으며, 이를 분석하여 그 결과를 도출하였다. (결과) 한국과 중국의 사례를 비교 분석한 결과, 한국은 원목을 활용함에 있어서 전통요소를 도입하여 장식적인 면과 공간적인 측면을 강조했다. 특히 실내디자인에서 색채와 재료의 조화, 공간의 가변성에 중점을 두었다. 중국은 한국과 유사하게 전통적인 요소를 도입하면서도 비교적 전통문양이나 패턴에 더 많이 활용했으며, 선적인 목구조나 격벽 등을 통해 공간의 깊이 감을 더 강조했다. 분석결과를 통해 현대의 원목 인테리어가 시각적인 심미성과 공간을 활용할 수 있는 기능적인 면을 강조한다는 것을 알아냈다. 한국과 중국의 원목 인테리어는 유사하면서도 상이하며, 서로의 사례를 참고하여 실내디자인에 적용한다면 색다른 원목 실내디자인을 만들어 낼 수 있을 것이다. (결론) 원목은 친환경적인 재료로서, 소비자가 추구하는 쾌적한 환경을 조성하고 소비자의 삶의 질을 높을 수 있다. 전통요소를 도입한 현대의 아파트 실내디자인은 전통적인 철학과 사상을 내포하고 있어 더 가치 있으며 미래에도 지속적으로 이용될 수 있다. 본 연구는 전통요소를 도입한 현대의 아파트 실내디자인에서 원목 활용 기법을 이해함으로써, 아파트 인테리어에서 원목이 어떻게 활용되고 있는지 파악할 수 있었다. 원목 인테리어는 현대인의 다양한 소비요구에 부응하면서 그것을 실현할 수 있는 가능성을 갖고 있어, 인테리어 디자인으로서 지속적으로 연구가 되어야할 것이다. 또한 연구를 진행함에 따라 추가적으로 거주자의 만족도나 반응 등을 조사한다면 소비자의 요구에 맞는 이상적이고 실행 가능한 인테리어 디자인을 제작할 수 있을 것이다. (Background and Purpose) Currently, apartments are the most popular type of accommodation. With social development and structural changes, people`s income and cultural competence have improved. Further, their lifestyle and accommodation preferences have diversified. Moreover, apartment sales have considerably increased. Along with the improvements in standard of living, consumers` choices have expanded as the materials used in designing the interior of residential spaces have diversified. This is the latest trend in interior design. As consumers` demands are changing, the apartment design techniques need to be explored accordingly. This study analyzes the modern apartment design technique that uses hardwood as the main material. Furthermore, if any apartment is designed using hardwood, this study can be used for reference. (Research Scope and Method) Based on existing literature and previous research, this study selects modern Korean and Chinese apartment designs that incorporated hardwood. Specifically, this study selects the most recognized model apartments in Seoul, Korea and Beijing, China that offer similar standard of living. In addition, these apartments were offered for the same price from 2013 to 2015. This study selects eight apartment designs used in Korea and China. After the analysis, this study leads to several results. (Results) After analyzing Korean and Chinese designs, this study confirms that Korean culture emphasizes decorative and spatial style by adding traditional elements such as hardwood. It particularly focuses on the harmony between color, material, and variability of space. China uses traditional patterns more often and emphasizes the sense of depth, using wooden structures and partitions. After analysis, this study confirms that modern hardwood-based interior design emphasizes the utility of visual aesthetics and space. The hardwood-based interior designs in Korea and China have both similarities and differences. If hardwood is skillfully incorporated into the interior design, it can create unique hardwood interior design. (Conclusion) As an eco-friendly material, hardwood will create a pleasant environment that consumers seek and will improve the quality of life. Modern apartment designs with traditional elements are based on the traditional philosophy that emphasizes value and continuity. This study reviews the use of hardwood in modern apartment design with traditional elements. The field of hardwood-based interior design needs to keep up with the varying demands of consumers, and further research is required to advance this field. In addition, research on consumers` satisfaction and responses will help to create ideal and feasible interior designs that meet their demands.

Effects of fireworks on air quality in the main urban area of Nanchong City during the spring festival of 2014-2019

Yifan Qian,Xu Yuan,Wen Dou,Jian Hu,Jie Xia,Danyu Li,Qing Zheng,Ping Zhang,Qiumei Quan,Yunxiang Li 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.2

The sources and variation trend of ambient air pollutants, the duration of pollution process and the conditions for decontamination were analyzed in this essay based on the ambient air pollutants data, PM<SUB>2.5</SUB> source analysis data and meteorological factors in Nanchong City during 2014 to 2019. The results indicated that the concentrated discharge of fireworks on New Year’s Eve was the main reason for the sharp deterioration of the ambient air quality. PM<SUB>2.5</SUB> and PM<SUB>10</SUB> concentrations increased significantly after fireworks were set off, and the peak value appeared at about 02:00 on the Lunar New Year’s Day, but the value of PM<SUB>2.5</SUB>/PM<SUB>10</SUB> did not change significantly. The concentration of SO₂ in gaseous pollutants was slightly affected by fireworks, while NO₂, CO and O₃ were not affected basically. Having been affected by fireworks, the concentrations and percentages of K⁺, Cl⁻ and Mg<SUP>2+</SUP> of the water-solubility ions in PM<SUB>2.5</SUB> significantly increased at the 0.01 level. Meanwhile, the concentrations and percentages of the metal elements, including Cu, Pb, Mg, Al, K and Ba, significantly increased at the 0.05 level. Restricted to the topography and meteorological factors, the duration of the pollution was prolonged.

Metabolizable energy requirement for maintenance estimated by regression analysis of body weight gain or metabolizable energy intake in growing pigs

Hu Liu,Yifan Chen,Zhongchao Li,Yakui Li,Changhua Lai,Xiang Shu Piao,Jaap van Milgen,Fenglai Wang 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.9

Objective: Feed energy required for pigs is first prioritized to meet maintenance costs. Additional energy intake in excess of the energy requirement for maintenance is retained as protein and fat in the body, leading to weight gain. The objective of this study was to estimate the metabolizable energy requirements for maintenance (MEm) by regressing body weight (BW) gain against metabolizable energy intake (MEI) in growing pigs. Methods: Thirty-six growing pigs (26.3±1.7 kg) were allotted to 1 of 6 treatments with 6 replicates per treatment in a randomized complete block design. Treatments were 6 feeding levels which were calculated as 50%, 60%, 70%, 80%, 90%, or 100% of the estimated ad libitum MEI (2,400 kJ/kg BW0.60 d). All pigs were individually housed in metabolism crates for 30 d and weighed every 5 d. Moreover, each pig from each treatment was placed in the open-circuit respiration chambers to measure heat production (HP) and energy retained as protein (REp) and fat (REf) every 5 d. Serum biochemical parameters of pigs were analyzed at the end of the experiment. Results: The average daily gain (ADG) and HP as well as the REp and REf linearly increased with increasing feed intake (p<0.010). β-hydroxybutyrate concentration of serum tended to increase with increasing feed intake (p = 0.080). The regression equations of MEI on ADG were MEI, kJ/kg BW0.60 d = 1.88×ADG, g/d+782 (R2 = 0.86) and MEm was estimated at 782 kJ/kg BW0.60 d. Protein retention of growing pigs would be positive while REf would be negative at this feeding level via regression equations of REp and REf on MEI. Conclusion: The MEm was estimated at 782 kJ/kg BW0.60 d in current experiment. Furthermore, growing pigs will deposit protein and oxidize fat if provided feed at the estimated maintenance level.

Fluorescent and Colorimetric Chemosensors for Anions, Metal Ions, Reactive Oxygen Species, Biothiols, and Gases

Yifan Liu,Ying Hu,이송이,이다영,윤주영 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.10

Colorimetric and fluorescent chemosensors have been actively studied in recent years, and this article covers our contributions to colorimetric and fluorescent chemosensors in detecting anions, metal ions, reactive oxygen species (ROS), reactive nitrogen species (RNS), biothiols, and gases. The chemosensors discussed in this article are categorized according to their corresponding analytes, and the final part is devoted to polydiacetylene-based chemosensors. We hope that this article will be beneficial in the design of chemosensors for various important analytes.

An Analysis of Indian Mentality towards China under the COVID-19 Pandemic

Juan Hu,Yifan Zhang,Yongjie He 한국국회학회 2020 한국과 세계 Vol.2 No.2

아시아에서 인구가 많고 영향력이 있는 두 국가인 중국과 인도의 관계는 지역 평화의 안정뿐만 아니라 세계적 국제정치차원에서도 중요한 역할을 한다. 2019년말 COVID-19 전염병 시작한 후 전 세계는 펜데믹의 영향을 크게 받았으며 이로 인해 인도의 경제도 역시 불안정해졌다. 인도의 국내 정치 및 경제도 크게 나빠졌으며, Narendra Modi 정부의 통치 기반도 크게 흔들고 있다. 이러한 상황에서 인도는 중국에 대한 태도를 바꿨다. 국내정치의 모순을 해결하기 위해 일부 인도정치 단체는 중국을 그 표적으로 삼았다. 2020년 5-6월에 중국군과 인도군이 Galavan Valley 경계 지역에서 충돌하면서 사상자가 발생하였고 이 사건으로 중국-인도 관계는 다시 악화되었다. 현재 중국과 인도는 잠시 Zero-Sum 게임에 빠졌지만, 전염병에 맞서기 위해 양국은 서로 협력이 필요한 파트너가 되어야 한다. 이 논문은 코로나 19 확산 이후 인도의 대중국 사고방식의 변화를 분석하고 중국-인도 관계 증진을 위해 몇 가지 의견을 제시하고자 한다. As two populous & influential countries in Asia, Sino-Indian relation plays an important part not only in regional peace and stability, but also at the global level. Since the outbreak of the COVID-19 Pandemic by the end of 2019, the global situation has been considerably affected by the Pandemic, the Indian economy has also been greatly de-stabilized. Domestic contradictions have accumulated and seriously shaken the ruling foundation of Narendra Modi s government. Under such circumstances. India s attitude towards China also fluctuated greatly. In order to transfer domestic contradictions, some political interest groups in India targeted on China. In May-June 2020, the Chinese and Indian armed forces clashed at the border area of the Galwan Valley, resulting in serious casualties, and the Sino-Indian relations have resurfaced. Apart from the inherent differences. India s attitude towards China was also a major inducement during the COVID-19 Pandemic. Under the COVID-19 epidemic, China and India were not two sides in the zero-sum game, but partners who needed further cooperation to combat the Pandemic. This paper analyzes the changes of India s mentality towards China after the outbreak of the COVID-19 Pandemic, and makes some thoughts on promoting Sino-Indian relations.

Loss and Efficiency Analysis of the Brushless Direct Current Motor with an Amorphous Stator Core

Lai Yifan,Hu Xiaolu,Shi Guibing,Yu Juntao,Wang Li,Gao Zhifeng 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.3

Due to the demand for energy conservation, the loss and efficiency of a brushless direct current (BLDC) motor is investigated. In order to improve the motor efficiency, we make efforts to reduce the loss by replacing the silicon steel (SS) stator with amorphous metal (AM) stator and improving the motor design. The motor performance is analyzed by simulations and experiments, and the processing influence on loss of AM material is also considered. It shows that the performance of the AM core deteriorates due to the stress introduced during the core processing, but the utilization of AM material and the optimization design can improve the motor efficiency by 4.76%. In addition, the weight of the motor is reduced by 11.36% than that of the initial motor. This research can provide a reference for the initial design and performance evaluation of AM BLDC motors.

Simulation of Non-Spherical Rice Seed Motion in Pneumatic Conveying with Bend by CFD-DEM

Jun Du,Yifan Heng,Junfang Xia,Mengjie Hu,Gang Zou 한국유체기계학회 2021 International journal of fluid machinery and syste Vol.14 No.3

The rice flow characteristics in pneumatic conveying determined the performance of pneumatic metering device for rice seed. The non-spherical rice seed motion in pneumatic conveying with bend was investigated by CFD-DEM simulation. The rice seed particle model was established by multi-sphere method, and a typical pneumatic conveying horizontal-vertical pipe with bend was selected. The applicability of three drag force models on non-spherical particle was compared. The particle flow characteristics in different pipes including the vertical-horizontal pipe and the horizontal-horizontal pipe were investigated. The non-spherical particle formed a particle rope at the outlet of bend, and the particle rope dispersed at downstream of the vertical pipe. The effect of particle shape on gas-solid flow characteristics was obtained. The gas velocity value in the bend for non-spherical rice particle was higher than that for spherical particle. The non-spherical rice particle rope dispersed more slowly than the spherical particle rope. The particle velocity profile of non-spherical and spherical particles was similar. The differences of the gas-solid flow predicted by Free stream model, Ergun and Wen & Yu model, and De Filice model were limited. The particle rope can also be formed in vertical-horizontal pipe and horizontal-horizontal pipe, but its dispersion represented different features. The results showed that particle shape and structure of pipe can influence the gas-solid flow characteristics, and a suitable particle model was important for the gas-solid flow simulation by CFD-DEM.

Investigation of the interstitial oxygen behaviors in vanadium alloy: A first-principles study

Xingming Zhang,Yifan Li,Qiaoling He,Ruilian Li,Lei Deng,Liang Wang,Xunlin Liu,Jianfeng Tang,Huiqiu Deng,Wang-Yu Hu 한국물리학회 2018 Current Applied Physics Vol.18 No.2

This study aims at characterizing the interstitial Oxygen (O) behaviors in the Vanadium (V) Alloy by means of the first-principles calculations. For this, the interations between vacancy (Vac) and O interstitil atom are studied in detail to obtain the binding energies and stable structures of the complexes. It can be seen that monovacancy binding with two O atoms occupied the opposing octahedral stie are particularly stable, and is liable to form VacO2 cluster in the V alloys. According to the mass action analysis, the predicted temperature dependence of the concentration for VacOn complexes are presented. Apart from monovacancy, we also consider the trapping behavior of vacancy cluster on the O atoms. The results also prove that one vacancy can trap two O atoms in the V alloys. Based the diffusion theory, we obtain the diffusion coefficients as a function of temperature with or without the vacancy effect in the V alloys. The predicted O diffusion coefficients in defect-free V alloys from our first-principles calculations are in excellent ageement with the experimental data, meanings that the vacancy-limited mechanism does not play the key role for O diffusion in V alloys. Regarding the interactions between vacancy, solutes and O atom, combining with the diffusion barriers of O affected by vacancy and solute, we infer the formation mechanism of the precipitates in the V alloys.

Virtual resistance with compensation link control strategy for traction network‑EMUs systems

Xuesong Zhou,Yifan Hu,Yu Tian,Tianqi Wang 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.4

A coupled system composed of a traction network and electric multiple units (EMUs) may oscillate or be prone to instabilitydue to the influence of the large number of nonlinear power electronic devices introduced by the EMUs. To solve thisproblem, this paper proposes a virtual resistance with a compensation link control strategy for the four-quadrant convertersof EMUs. First, based on the actual background, input and output impedance models of the coupled system are established,including the output impedance model of the traction network and the input impedance model of the EMUs. Based on theabove models, the factors affecting the stability of the coupled system are analyzed by utilizing the impedance matching analysis method and the generalized Nyquist stability criterion (GNC). In the proposed control strategy, virtual resistance is used to adjust the loop gain and to increase system damping, which can improve the stability margin of the system. Virtual resistance can also increase the initial power equivalent to improve system stability. The introduction of the compensation link is to suppress the increasing tendency of the intermediate DC voltage steady-state error caused by the virtual resistance. The parameters of the virtual impedance and the compensation link are designed by forbidden region criterion to meet engineering requirements. With the proposed control strategy, the maximum EMU number to ensure system stability has been significantly increased. Finally, simulations and experiments verify the correctness of the analysis and the effectiveness of the proposed control strategy.